Severe Fabric Moire

satokome@comcas · #1 11-25-2004, 12:57 AM

Hi, this is my first post and need some expert help to fix this image shot by a professional photographer's digital camera. It contains really bad fabric moire patterns all over the bag, especially on the silver fabric as well as some part of red fabric. Can anybody help me on this one? I tried everything I know and cannot make it work.

Tried to fix it in LAB mode: blurring A & B channels won't help as moires are in the Lightness channel. All channels in all modes contain the moire (CMYK and RGB). Anything can be done to fix this image?

Satoko :-(

Leah · #2 11-25-2004, 01:49 AM

Frankly, if it was a professional photographer you ought to be able to get them to reshoot.

I have not got rid of all of it by any means as I only had 5 minutes -- but what I tried was adding a new layer in Overlay blend mode, filled with 50% grey. Then brushing onto that with a small soft brush at low (less than 10%) opacity using black to darken and white to lighten. I have at least been able to make a start on reducing the effect.

[Edit: Hmm, you really need to view it full-size to see that I have managed to reduce the effect. If your browser shrinks it down to fit the screen size then it looks pretty much the same.]

satokome@comcas · #3 11-25-2004, 02:16 AM

I will need to try it. Thanx. I knew it's going to be time-consuming. Whatever it takes. (Unfortunately, I cannot have him reshoot as my boss already paid him for the job, and I'm the one who needs to fix it.)

john_opitz · #4 11-25-2004, 02:49 AM

To see if their is moire in a fabric. You should view it at actual pixels (100%).

john_opitz · #5 11-25-2004, 03:54 AM

Try using the dust & scratches filter. Make three layers (duplicate) from the background. The first duplicate, change the blending mode to "Darken". Apply the dust & scratches filter(the setting "I" used was radius 8, threshold 6). The second duplicate change the blending mode to "lighten". Apply the dust & scratches filter (setting "I" used was radius 9, threshold 6). The third duplicate, leave as is (normal)........To this third duplicate, add a (black) layer mask (hide all). On this layer mask, paint with white (only the area that is affected by moire). Most of the time I use actions (for speed) for this type of work. The action I used was not designed for this type of moire. I use a different type (commands) for other fabric moire. With this kind of material is different than most clothing fabric.

John

john_opitz · #6 11-25-2004, 04:00 AM

I'm sorry.....correction.! On the layer mask. I said: Black (hide all). It should be, white (reveal all). And paint black on it.

John

byRo · #7 11-25-2004, 07:42 AM

Hi there, Satoko,

If you take some time to read my little tutorial about the radius of High pass filters and Gaussian blurs, you'll see that depending on the radius you will se different information from the photo.

In this case the information of the fabric's weave pattern is at a very low radius while the Moire pattern is at a larger radius. This gives us enough to set up an adjustment to diminish one but save the other:

(the exact How's and Why's would take up a whole tutorial - here just the part that does the work)

- Duplicate the background layer;
- On this duplicate layer apply the High-pass filter at radius (3.8)
- Apply a Gaussian blur to this at radius (0.9)
- Invert the layer;
- Set blending to Linear Light;
- Set opacity at 50%;
- Mask to show only where you want to take out the Moire.

This may not take out 100%, but it does a good job and keeps things looking natural.

byRo

satokome@comcas · #8 11-25-2004, 01:23 PM

Good stuff. Although it doesn't take the moire out 100%, your solution looks most natural as it preserves the fabric wave which I need to retain. I'll use this technique although I still need to do some more local retouching as Leah suggested. U are the best!

Satoko :-D

satokome@comcas · #9 11-25-2004, 01:39 PM

Thank u, John. I'm interested to know what u do with other kind of fabric moire as I also got common fabric moire with other products as well. Those are just plain black fabric, and I'm sure I can use your expertise to eradicate them. Setting up actions for this type of work will sure reduce my pain!

Satoko

john_opitz · #10 11-30-2004, 08:25 PM

Sorry, I'm replying back so late.

<<I'm interested to know what u do with other kind of fabric moire as I also got common fabric moire with other products as well>>

To be honest with you., I don't come across this type of moire anymore. And, I prevent moire from happening from the begining. So I don't put a lot of effort into moire cures anymore. The new cameras (high-end cameras anyway) they have out now, are pretty good for moire problems of the past. As well as the noise problem of the past. And the people I deal with (art directors, ect...ect...) don't accept these kind of images, anymore. Example, how its changing......A stock agency (others are following) will not accept film anymore (as of Oct. 2004). They will only accept digital files from 8-MP cameras or better. They will not even accept scans from negs. One would think, how can they tell if a file is from a certain camera and if it is from a 8-MP camera? Well.....The only thing I can say is..... Don't strip out that meta data! They get mad at that! It's a red flag.
But the moire that I have come across is very, very faint, that a blend ("a" or "b" channel, modes: either, overlay, softlight, hardlight) into the L (sometimes inverted) of LAB, will take care of it. After the blend, I then blur the "a", "b" channels. Yes..... I do that after.
If your a photographer and run across these moire problems. Camera Companies have a new line of lenses (for digital) out for their D-cams that takes care of moire problems as well. There are filter companies out their that make filters (screw-in type) for the moire problem too. BTW. This is nothing new, though. A camera company always had one for their D-cam. Use was optional. And pricey!

With this kind of moire in the file, I agree with leah.
<<Frankly, if it was a professional photographer you ought to be able to get them to reshoot.>>

john_opitz · #11 11-30-2004, 08:39 PM

Also, when you shoot with a D-cam. You can view the preview. And take measures from their. Unlike film and conventional cameras, you get to see the preview with digital right away. Big plus, here. This is the way an art director would look at this. If I were to do this... I would be put in the mail room. Licking letters with cyanide on the adhesive.